Aspect Ratio Calculator
Resize keeping proportions, 16:9 etc.
Loading tool…
About the Aspect Ratio Calculator
Calculate aspect ratios and resize dimensions proportionally: enter an original width × height to get the simplified ratio (16:9, 4:3…), then enter a new width to get the matching height. Presets for common video, photo, and social-media ratios, plus a visual preview.
How to use
- 1Enter the original width and height (or pick a preset).
- 2Read the simplified ratio.
- 3Enter a new width — the proportional height appears instantly.
Related Numbers & Math tools
Aspect Ratio Calculator is part of DevKit — 100 free, privacy-first tools for developers, students, and everyone, built by Minhazul Ashim. Everything runs in your browser; your data never leaves your machine.